osx man page for segedit

SEGEDIT(1)						      General Commands Manual							SEGEDIT(1)

NAME
       segedit - extract and replace sections from object files

SYNOPSIS
       segedit	[  option ] name ...  input_file [-extract segname sectname filename] ...  [[-replace segname sectname filename] ...  -output out-
       put_file]

DESCRIPTION
       Segedit extracts and or replaces the named sections from the input_file and creates an output_file (if replacing a section).   The  segment
       and  section  names  are the same as specified to ld(1) with the -segcreate option.  The segment and section names of an object file can be
       examined with the -l option to otool(1).  Only sections in segments that have no relocation to or for them can be replaced (marked with the
       SG_NORELOC segment flag) but all sections can be extracted.

       The options to segedit(1):

       -extract segname sectname filename
	      Extracts the section specified by the segment name section name pair and places the contents in the specified filename.

       -replace segname sectname filename
	      Will  replace  the section specified by the segment name section name pair and places and take the new contents for the section from
	      the specified filename.  The -output filename option must also be specified.  The resulting size of the section will be rounded to a
	      multiple of 4 bytes and padded with zero bytes if necessary.

       -output output_file
	      Specifies the output file to create when replacing sections.

SEE ALSO
       ld(1), otool(1)

LIMITATIONS
       Only mach-O format files that are laid out in a contiguous address space and with their contents ordered in the order of increasing address
       can have their segments replaced by this program.  This layout is what the link editor produces by default.

Apple Computer, Inc.						 October 23, 1997							SEGEDIT(1)